title: Impaired critical period plasticity in primary auditory cortex of fragile X model mice.
abstract: Fragile X syndrome, the most common form of heritable mental retardation, is a developmental disorder with known effects within sensory systems. Altered developmental plasticity has been reported in the visual and somatosensory systems in Fmr1 knock-out (KO) mice. Behavioral studies have revealed maladaptive auditory responses in fragile X syndrome patients and Fmr1 KO mice, suggesting that adaptive plasticity may also be impaired in the auditory system. Here we show that, whereas tonotopic frequency representation develops normally in Fmr1 KO mice, developmental plasticity in primary auditory cortex is grossly impaired. This deficit can be rescued by pharmacological blockade of mGluR5 receptors. These results support the mGluR hypothesis of fragile X mental retardation and suggest that deficient developmental plasticity may contribute to maladaptive auditory processing in fragile X syndrome.
authors.affiliation: Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720.
authors.forename: Heesoo
authors.initials: H
authors.lastname: Kim
authors.forename: Robert
authors.initials: R
authors.lastname: Gibboni
authors.forename: Colleen
authors.initials: C
authors.lastname: Kirkhart
authors.forename: Shaowen
authors.initials: S
authors.lastname: Bao
mesh_terms: D000818:Animals; D001303:Auditory Cortex / Q000187:drug effects / Q000503:physiopathology*; D003423:Critical Period, Psychological; D004195:Disease Models, Animal; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics; D005600:Fragile X Syndrome / Q000503:physiopathology*; D051379:Mice; D018345:Mice, Knockout; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D064529:Receptor, Metabotropic Glutamate 5 / Q000037:antagonists & inhibitors
chemical_list: D018691:Excitatory Amino Acid Antagonists; D051860:Fragile X Messenger Ribonucleoprotein 1; D011725:Pyridines; D064529:Receptor, Metabotropic Glutamate 5; C497684:Fmr1 protein, mouse; C121465:6-methyl-2-(phenylethynyl)pyridine